A face mask for ventilation of a patient. The sensor provides two output signals, one indicative of an air-fuel ratio and the second indicative of a NOx concentration. An intermediate layer having a precisely controllable thickness is arranged between the gate electrode and the spacer. The control surface is turned, at a predetermined respective rate of turn, into a predetermined respective position to modify lift profile of the wing along a wingspan length to reduce lift in at least one buffeting-generating region of each wing. Before copying, the host instructs a disk array device to identify the states of target logical volumes and collect information in control memory, whereupon the disk array device reads information in the control memory and reports information relating to the target logical volumes to the host.